GO处理一些未知结构的JSON，纠结一个星期了

这是elasticsearch的返回结构，aggregations中的user、tags、ct等都是不可预知的字段，要如何取出这些结构，并还原成一维map？ ```json { "took": 2, "timed_out": false, "_shards": { "total": 5, "successful": 3, "failed": 0 }, "hits": { "total": 22, "max_score": 0, "hits": [] }, "aggregations": { "user": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "olivere", "doc_count": 16, "tags": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "golang", "doc_count": 16, "ct": { "value": 16 } }, { "key": "elasticsearch", "doc_count": 7, "ct": { "value": 7 } } ] } }, { "key": "sandrae", "doc_count": 6, "tags": { "doc_count_error_upper_bound": 0, "sum_other_doc_count": 0, "buckets": [ { "key": "cycling", "doc_count": 6, "ct": { "value": 6 } }, { "key": "sports", "doc_count": 6, "ct": { "value": 6 } } ] } } ] } } } ```